Simple way to monitor network traffic for LTE router?

Hi guys, need some assistance.

I have a huawei b818 router, it will show what devices are connected and the total speed being used but doesn't provide a breakdown on what device is using the data.

What would be the best option? (router doesn't support snmp)

I Have a spare box sitting there, or a netgear D7000 router spare.

Any suggestions welcome!